IJEE Educational Data Mining

Histograms and results of k-means and Ward's clustering for IJEE special issue<br><br>The fileset contains information from three sources:<br><br>1. Histograms (two files):<br>* Lexical_histogram.png (histogram of lexical errors ratios)<br>* Grammatical_histogram.png (histogram of grammatical erros ratios)<br><br>2. K-means clustering (eight files):<br>* elbow-lex.png (clustering by lexical aspects: error curves obtained for applying elbow method to determinate the optimal number of clusters)<br>* cube-lex.png (clustering by lexical aspects: a three-dimensional representation of clusters obtained after applying k-means method)<br>* Lexical_clusters (table).xls (clustering by lexical aspects: centroids, standard deviations and number of instances assigned to each cluster)<br>* elbow-gram.png (clustering by grammatical aspects: error curves obtained for applying elbow method to determinate the optimal number of clusters)<br>* cube-gramm.png (clustering by grammatical aspects: a three-dimensional representation of clusters obtained after applying k-means method)<br>* Grammatical_clusters (table).xls (clustering by grammatical aspects: centroids, standard deviations and number of instances assigned to each cluster)<br>* elbow-lexgram.png (clustering by lexical and grammatical aspects: error curves obtained for applying elbow method to determinate the optimal number of clusters)<br>* Lexical_Grammatical_clusters (table).xls (clustering by lexical and grammatical aspects: centroids, standard deviations and number of instances assigned to each cluster)<br><br>3. Ward’s Agglomerative Hierarchical Clustering (three files):<br>* Lexical_Cluster_Dendrogram_ward.png (clustering by lexical aspects: dendrogram obtained after applying Ward's clustering method).<br>* Grammatical_Cluster_Dendrogram_ward.png (clustering by grammatical aspects: dendrogram obtained after applying Ward's clustering method)<br>* Lexical_Grammatical_Cluster_Dendrogram_ward.png (clustering by lexical and grammatical aspects: dendrogram obtained after applying Ward's clustering method)<br>* Lexical_Grammatical_clusters (table).xls: Centroids (from column 2 to 7) and cluster sizes (last column) obtained by applying Ward's agglomerative hierarchical clustering to lexical and grammatical error ratios.<br>* Grammatical_clusters (table).xls: Centroids (from column 2 to 4) and cluster sizes (last column) obtained by applying Ward's agglomerative hierarchical clustering to grammatical error ratios.<br>* Lexical_clusters (table).xls: Centroids (from column 2 to 4) and cluster sizes (last column) obtained by applying Ward's agglomerative hierarchical clustering to lexical error ratios.<br><br>